Well. You could make a Template Variable where the user has to enter the Youtube ID. Apart from that, the embed code of a youtube movie is always the same. You can integrate the embed code directly into your template and write the id dynamically from the TV. Thus, the user only has to upload a movie and enter the youtube ID in the TV field.
Edit:
Here’s how you could do it. Integrate the following code into your Video-Template and create a Template Variable named "YouTubeID" and "attach" it to the Template. If you enter a correct YouTube ID in the Template-Variable, your site should then show the Video correctly.
<object width="425" height="355">
<param name="movie" value="http://www.youtube.com/v/[*YouTubeID*]&rel=1"></param>
<param name="wmode" value="transparent"></param>
<embed src="http://www.youtube.com/v/[*YouTubeID*]&rel=1" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355">
</embed>
</object>
To answer your question: Using youtube surely is not the easiest thing ever. But i guess it is one of the easiest ways to publish Video
without knowing too much about video-formats, codecs etc. Youtube will convert all videos to the flash video format. The drawback of this approach is, that you’ll have a youtube "branded" video-player on your site and a delay when uploading movies. You’ll have to wait quite some time until a video is available after upload.